Add Coroutines support for repository event handler

[sbont]

When implementing a repository event handler in Kotlin, marking it as suspend fun causes an IllegalArgumentAxception: "wrong number of arguments".
After some digging I found that a suspending function compiles to method expecting a kotlin.coroutines.Continuation as second parameter, and it seems to be unable to resolve this.

@Component
@RepositoryEventHandler(MyEntity::class)
class MyEntityEventHandler() {
    @HandleBeforeDelete
    suspend fun handleMyEntityDelete(value: MyEntity) {
//        logic
    }
}

[mp911de]

See also spring-projects/spring-framework#28343